BBC BASIC Programmers' Reference

by Jon Ripley, May 2007

To read the MIME type of a file call “FN_GetMIMEType” passing it a file extension, for example:

        PRINT "The MIME type of a .html file is ";FN_GetMIMEType("html")

The code for “FN_GetMIMEType” is:

        DEF FN_GetMIMEType(T$)
        LOCAL B%, H%, L%, R%, T%
        L% = 255 : DIM B% LOCAL L%
        SYS "RegOpenKeyEx", &80000000, "."+T$, 0, &20001, ^H% TO R%
        IF R% = 0 THEN
          SYS "RegQueryValueEx", H%, "Content Type", 0, ^T%, B%, ^L% TO R%
          REM Uncomment the next line to set a default MIME type if none is found
          REM IF R% $$B% = MIMEDefault$
          SYS "RegCloseKey", H%
        ENDIF
        = $$B%

“FN_GetMIMEType” returns an empty string if no MIME type is found in the registry for the requested file extension. To set a default MIME type for all unknown extensions uncomment the specified line and replace MIMEDefault$ with your fail safe type.